Yes, but the longer shutter open time may allow some things to go wrong while the shutter is open. Base ISO and a long shutter is great for astrophotography with a K-5 and later Pentax body but you need NR on for dark frame subtraction. For me most of my shooting history is sports so wide open apertures, fast shutter speeds, and screw the ISO.

In your case I would be experimenting with different settings to see what is best. Definitely delay the shutter to get MLU done early.